>> rod rosenstein: barry landau was a con artist.reputation as a presidential historian in order to gain the confidence of museums and other people who had custody of important documents. and then he stole them. it was a reputation, it turns out, that was the product of his rich imagination. landau claimed he'd worked for every president since lyndon johnson, had served as chief of protocol at the white house. >> rosenstein: but in fact, there is no evidence that barry landau was ever employed by any white house, or had any of the relationships he claimed to have, or indeed had any legitimate job at all. >> simon: the landau case, and a few others, let law enforcement know they had a problem they hadn't really been aware of until very recently. >> paul brachfeld: every institution now that has collections is threatened. we all know that there is a major threat and it's getting larger. >> simon: former secret service employee paul brachfeld is the inspector general of the national archives. he runs the tiny and little- known archival